Tagged Questions

A device which controls the voltage and current being delivered to a capacitor or battery.

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1
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1answer
36 views

Power a laptop LED backlight with NiMH batteries

I'm powering a laptop LED backlight with an external 24,8V power supply, because I have problems with the internal WLED driver. The display used to work at 27V, but with the 24,8V of the power supply ...
0
votes
1answer
37 views

High Cell Count LiPo Balancer/Charger

How would I go about balance charging either 100 or 75 lipo cells? This is a very serious question by the way, it's for an electric vehicle and we use either 75 or 100 cells at a go and currently ...
0
votes
2answers
47 views

mobile battery charging using voltage regulator?

Circuit shown at http://www.instructables.com/id/9v-USB-charger/ will that satisfy all condition of mobile charging through usb ? what is advantage of circuit shown at ...
0
votes
1answer
65 views

Turn Laptop Battery to a Power Bank

Is it possible to turn a laptop battery into a power bank? I have seen video tutorials and articles on how to turn AA Batteries into power banks, however, no one has created a power bank using a ...
-1
votes
1answer
59 views

We're making a bike-powered USB charger and we have (almost) no idea what we're doing

So my friend and I are going to build a USB charger powered by a dynamo. Here is a diagram of what we are planning to do. I have a few questions: 1.) How do we test if the dynamo and breadboard ...
-1
votes
1answer
77 views

Need to make a laptop charger [closed]

I am not an electrician. My laptop's charger burned when we had high voltage 2 days ago. My laptops charger says Output is: 19.5 V and 9.23 A. I am in a country that you can't easily find those kinds ...
0
votes
2answers
81 views

5 volt generator

first time question, and not much of an electrical guy. so please be patient. My dad however, is an electrical engineer, who loves little goofy gadgets as most engineers do. For Christmas I want to ...
0
votes
1answer
48 views

Charge a Lipo battery and power a circuit

I purchased this LiPo charger and I plan to connect the GND and BAT connections to the battery and an external circuit at the same time. In the datasheet the reference drawings are for battery ...
1
vote
1answer
40 views

Charging appliances with chargers of different amperage (safety & duration)

Safety Will the battery or charger be damaged if I use a 1A charger to charge a 2.1A appliance? Will the battery or charger be damaged if I use a 2.1A charger to charge a 1A appliance? Duration I ...
1
vote
1answer
43 views

Identifying a four-pin IC labelled EL 8+7 G8025

I want to know the purpose of a component named "EL 8+7 G8025" which was found inside a Nokia charger.
0
votes
1answer
56 views

lm2596 fixed 5 volts(usb) from 12v 10W solar panel

I have got a 10 Watt solar panel & a 10000 mha Battery bank. I plan to use the panel to charge the battery bank. I have a LM2596(variable configuration with pot), I plan to use it to charge my ...
0
votes
1answer
42 views

Do AA battery chargers detect battery charge level and automatically turn off when full? [closed]

When I put in AA batteries for charging, do I have to remember to disconnect the charger after the specified number of hours, or does the charger detect the charge level and automatically turn off ...
1
vote
1answer
89 views

Why are 5 Volt 7-8 Amps chargers not available for charging phones quickly? [closed]

Available phone s chargers have either 0.5, 1, 2 Amps rating depending on the batteries (varied capacity) used. Why is it that 7, 8 Amps chargers are not available ? if the limitation is in the ...
1
vote
2answers
84 views

My voltage multiplier (cockroft-walton) will not charge my capacitor bank past 150v. How can I fix this?

I got 5 free 450v 4700uf capacitors that I put in parallel to form a 23500uf 450v capacitor bank (2.4kJ) in hopes of building a can crusher and later a railgun. I built a voltage tripler from four ...
2
votes
2answers
162 views

How does a USB 2.0 Wall Charger negotiate current output?

I'm trying to use a mobile phone charger for my projects, and want a high current output. I have read this, however my measurements show something else. Here is a link to the Battery Charging ...
0
votes
1answer
71 views

NiMH battery charger using discrete elements

Below is a schematic of NiMh battery charger that must automatically switch off charging current when battery is fully charged. I am aware that the main part of this scheme is current source, build ...
-1
votes
2answers
88 views

Issue charging a 12V battery using solar charger

I bought a 12V solar charger for vehicle batteries, because I am usually using wall chargers and I wanted to give green technology a try. When I connect the solar charger to my battery, it shows 10V, ...
2
votes
1answer
510 views

How can I extend this circuit to use it in our real life?

I am planning to design a wireless mobile charger circuit next week. For that purpose, I have selected the circuit which is shown below and is collected from the post: wireless mobile battery charger. ...
2
votes
2answers
225 views

Supercap charging circuit for RTC backup on STM32

I'm asking for a reliable/simple/cheap circuit for the VBAT section of a STM32 design, powered at VDD=3.3V, that will safeguard the built-in RTC (based on 32768 Hz Xtall) for like 10 days. Based on ...
1
vote
4answers
177 views

Battery-Operated Mobile Charger

I want to build a mobile charger that is battery operated and found this diagram. At first glance, this diagram looks kinda simple and I thought that this won't work. I'm a newbie on making this kind ...
1
vote
3answers
152 views

Rate my Rasberry Pi UPS

I've made simple schematic for a UPS for Raspberry Pi. It contains a 12V Lead Acid Battery (40Ah), 5V LM7805 regulator and some capacitors. I'm supposing max 1.2A load from Raspi. Should I add ...
2
votes
2answers
86 views

How to reduce voltage of a dynamo to 5 volts

A friend and I are going to make a bike-powered charger. There is a video of KipKay making one. But he uses a 12 volt 6 watt dynamo and there is a schematic that he follows to lower it to 5 volts. Can ...
-1
votes
1answer
122 views

How to fix exposed wire at the end of a laptop charge with electrical taper [closed]

I have a Toshiba L505D-S5965 with Windows 8.1. My charger has exposed wire at the end but it was working until a few days ago. It's at the part where it's plugged to the laptop charger port. Now it ...
0
votes
3answers
89 views

Method to lower voltage of a laptop charger

I bought an IMAX B6 LiPo Balance charger that needs as input 11-18V but I have an unused laptop charger (the laptop is gone) having 19V with 4.74A. What is the easiest method to lower the voltage to ...
0
votes
2answers
109 views

Charging supercapacitors with Buck converter. Do I need to cut power once charge is reached?

I am trying to build a supercapacitor charger, and as I don't particularly have a good handle on the risks of such a thing, I'm hopping on here to give some information. I am using a buck converter ...
1
vote
1answer
90 views

Question on 3DS power adapters, minor voltage difference [duplicate]

I am going to be traveling overseas and bringing my Nintendo 3DS which the adapter outputs DC 4.6V 900mA. I found an unofficial USB cable to charge it and I was curious if the minor variance in the ...
0
votes
3answers
149 views

Will a dual car charger that shows a maximum output of 2000mA produce a 2.1A current?

I have a dual car charger that states input is 12-24VDC and Output is maximum of 2000mA, but it is supposed to have one port charge at 1A and other port charge at 2.1A. Is the 2.1A output possible ...
0
votes
4answers
99 views

What is this electronics component?

What is the yellow component shown here? This is off a Outlet USB phone charger.
0
votes
1answer
79 views

LiPo Charger question [closed]

I'm not into electronic so this is why I ask people who know. I have an opportunity to buy a 5,000 mAh LiPo charger but I will use it to charge up to 14.8V 8,000 mAh batteries. Will it charge the ...
0
votes
1answer
49 views

What is a good NiMH charger? [closed]

I have some (cheap/old?) batteries that I need charged. The problem is, the chargers I have keep charging them until they get overcharged and lose their capacity. I already ruined 4 ...
1
vote
2answers
89 views

Why one transistor switches on first than other

In the circuit diagram given below we have two transistors. And in the article it is given that one transistor will turn on first. Why this transistor turns on first
0
votes
0answers
74 views

homemade hub dynamo usb charger

I just made an usb charger to connect to my hub dynamo. ->voltage rectifier -> smoothing capacitor -> low voltage drop 5V regulator -> female usb port So now I can power / charge my mobile phone and ...
1
vote
4answers
158 views

Will voltage or current determine a diode drop for this battery charging circuit?

I am using a li-ion battery charger IC that regulates an output to 4.2V. I have a schottky diode in series with the output that then connects to the battery. How do I determine the voltage drop? If ...
-1
votes
1answer
108 views

What do B+ and C+ mean on the wires of a Lifepo4 battery pack?

I bought this Lifepo4 battery pack. It came with its own charger. The seller told me the charger can be connected directly to the battery. There are 4 cables coming out of the battery: C+, C-, B+ and ...
1
vote
1answer
193 views

Efficient power utilization by MPPT battery charger

I am designing an MPPT solar charge controller to get more efficiency out of my system. At the moment I am at the conceptual stage and I have some questions about MPPT battery charging in general. ...
-1
votes
1answer
167 views

Transmitting 12v DC over a long wire

I'm trying to charge my laptop through a 12V battery and 12-19V adapter over a long wire but I've noticed that the adapter makes some noise and doesn't work. On the other hand when I connect it close ...
0
votes
2answers
69 views

DC output of phone charger [duplicate]

I have a nokia phone charger which has the following specifications: Input: AC 100-240 V, 50-60 Hz, 100 mA Output: DC 5.0 V, 350 mA When I checked the output of the charger with a multimeter it ...
0
votes
0answers
105 views

LiPo combination usb/dc/solar charger + fuel monitor

I'm trying to roll several LiPo boards available on Sparkfun/Adafruit into one multipurpose board. Not a very ambitious project I know, but I'd really like an all in one. I've seen Sparkfun's LiPo ...
0
votes
1answer
60 views

Can someone tell me if this topology for a crude battery charger is sound? Block diagram included

I am making a portable phone charging battery for fun. I have a micro USB input that ties to a 5V - 4.2V buck converter to charge a li-ion battery. The IC is made to charge batteries so I think that ...
0
votes
1answer
115 views

Can I use a 7805 as a current regulator?

Can I use 7805 as current regulator? My input is 12-14 V DC (battery) and I require output 5V and 500mA or adjustable. My background is CS so unaware of these ICs. I have searched LM317 and LM338 but ...
2
votes
2answers
375 views

Is it ok to use an old phone as an universal battery charger?

We know that a charger is just an adapter that supplies a constant voltage (5 volts usually). The actual charging circuit is in the phone itself. With a bit of soldering and wiring, can I use my old ...
0
votes
1answer
264 views

Battery charging: Absorption Charge Stage

I need some help in understanding basic battery charging. I read about the three common stages: Bulk Charging, Absorption Stage and Float Stage, but I can't understand exactly what the controller does ...
2
votes
1answer
176 views

LiPo use while charging: two cells (one charging, one under load)

I'm trying to figure out how to power my project using LiPo batteries and a solar charging circuit. The project will draw up to 2A at 3.3V. I did a search for IC LiPo charging chips that also allow ...
1
vote
2answers
129 views

Charging 12V SLA from Single Solar Cell

I'm interested in charging a 12V Sealed Lead-Acid battery from a single monocrystalline solar cell. The solar cell's voltage is only 0.5V at maximum power point, but it supplies 8A. I will need a 32X ...
0
votes
1answer
93 views

Trigger charge in Android phone using a PIR

I want to use my android phone + 1 PIR as a poor man's home alarm. I need the phone to be triggered somehow when the PIR detects motion. I was looking at the IOIO board. But wouldn't even be easier ...
1
vote
1answer
138 views

Is the DESIGN of an MPPT Solar charger SUPPORTING combination with regular battery charger on the LOAD side? [closed]

I just got my "LCD 30A MPPT Solar Panel regulator" for my caravan, but connecting it raised an issue. It looks like this: ...
2
votes
2answers
465 views

How do we charge a small 12V battery from a large 12V battery bank

In a youth organization that I am part of we are building a traveling stand alone system, which will be put up on various fairs and music festivals. On one of the festivals there is a wish that we can ...
1
vote
3answers
109 views

Please help me understand this charging algorithm

I am trying to plan a stand alone system, and for that I will need a charge controller. I am looking at a few models from the company MorningStar. I have understood what MPPT is, and decided to not ...
1
vote
1answer
353 views

Charging 7.4V Li-Ion battery

I'm making a battery out of two 3.75V Li-Ion cells to go into a speaker system that powers an amplifier. I was wondering on the PCM, how many volts would be max to charge these cells? The cells I have ...
0
votes
1answer
64 views

ICSwitching between solar panel and batteries

I would like to charge the NiMH batteries, when there is excess power from the solar power and use the power stored in the batteries, when I need it (to drive a motor and at night). I have the ...